Stabilization of fatty materials



STABILIZATION F FATTY MATERIALS Joseph A. Chenicek, Bensenville, Ill.,assignor to Universal 011 Products Company, Des Plaines, 111., acorporation of Delaware 'No Drawing. Application November 30, 1954Serial No. 472,209

18 Claims. (CL 99-163) the-present invention generally are of animal,marine or vegetable origin. Merely as typical representatives, thefollowlng edible fats and-oils are mentioned: linseed oil, menhaden oil,cotton seed oil, castor oil, rapeseed oil,

coconut oil, peanut oil, corn oil, sesame oil, palm oil,

babassu oil, butter, fat, lard, beef tallow, etc., as .well. ashydrogenated oil and fats which are sold under various trade names. Itis understood that other oils and fats United States Patent 0 may betreated Within the scope of the present invention,

including fats and oils which previously have been subjected to varioustreatments, such as blowing with air, heat treatment, etc. i

In addition, the present invention may be employed for the treatment ofsolid food products including, for example, bellies, sides or slabs ofbacon, slabs-of ham, sides of beef, as well as similar cuts of sheep,lamb, deer, etc. -When used for feed to dogs or other animals, thepresent invention may be utilized for the treatment of horse meat, etc.Similarly, the present invention may be used for the stabilization of'poultryincluding chickens, ducks, geese, turkeys, etc., marine foodincluding fish, lobster, etc., fruits including oranges, pineapples,bananas, etc., vegetables including egg plant, squash, avocados, etc.,

Patented Oct. 14, 1958 2 be readily soluble in edible fats and oils inorder to be satisfactorily incorporated therein.

In one embodiment, the present invention relates to a method ofstabilizing fatty material against rancidity which comprisesincorporating therein an N,N-di-aliphatic'-pphenylene diamine inhibitorin which each aliphatic group contains at least 8 carbon atoms.

In a specific embodiment, the present invention relates to a method ofstabilizing lard which comprises adding thereto from about 0.000l% toabout 1% by weight of N,N-di-octyl-p-phenylene diamine.

In another embodiment, the present invention relates to a novelcomposition of matter comprising a fatty material containing anN,N-di-aliphatic-p-phenylene diamine in which each aliphatic groupcontains at least 8 carbon atoms.

As hereinbefore set forth, the inhibitor of the present inventioncomprises an N,N'-di-aliphatic-p-phenylene diamine in which each of thealiphatic groups contains at least 8 carbon atoms. In a preferredembodiment, each of the aliphatic groups in theN,N-di-aliphatic-p-phenylene diamine contains from about 8 to about 20carbon atoms, although in some cases a higher number of carbon atoms ineach of the aliphatic groups may be employed. Generally it will beunnecessary to exceed about 30 carbon atoms in each of the aliphaticgroups. Preferred additives comprise N,N-di-alkyl-p-phenylene diaminesincluding N,N'-di-octyl-p-phenylene diamine, N,N dinonyl-p-phenylenediamine, N,N-di-decyl-p-phenylene diamine, N,N'-di-undecyl-p-phenylenediamine, N,N-didodecyl-p-phenylene diamine, N,N-di-tridecyl-p-phenylenediamine,N,N di tetradecyl p phenylene diamine,N,N-di-pentadecyl-p-phenylene diamine, N,N-di-hexadecyl-p-phenylenediamine, N,N'-di-heptadecyl-p-phenylene diamine,N,N'-di-octadecyl-p-phenylene diamine, N.N-di-nonadecyl p-phenylenediamine, N,N-di-eicosylp-phenylene diamine, etc.

Particularly preferred inhibitors comprise those in which the alkylsubstituents are attached to the nitrogen atom on a non-terminal carbonatom and still more particularly comprise a secondary alkylconfiguration.

' Specifically preferred inhibitors thus include N,N-di'3- dairyproducts including cheese, dried milk powder, etc.,

confectioneries and particularly chocolate, butter creams, etc. It isunderstood that the foodproducts specifically set forth herein aremerely typical representatives and that the novel features of thepresent invention may be utilized for the-stabilization of any foodproduct subject to oxidative deterioration. 'In still anotherembodiment, the novel inhibitor may be incorporated in material used topackage food products, including, for example, wax paper, coatedcartons, etc.

terial or food product is stabilized by the addition thereto .of a novelinhibitor. Satisfactory inhibitors for fatty materials must meet certainstrict requirements. In the first place, the inhibitor must be potent inorder In accordance with the present invention, the fatty maprevent orretard rancidity development. Extensive innot be satisfactory for use inother organic substances.

Further, satisfactory inhibitors for fatty materials must bench-toxic,must not impart undesirable color, ordor or-taste to the fats and oils,and must not be so volatile that they are removed from the fats andoilsduring cook- 1 ing or in deep fat frying. In addition, the inhibitormust (S-methylheptyl)-p-phenylene diamine, N,N-di-4-(2,6-

dimethyl-heptyl)-p-phenylene diamine, N,N-cli-2-octyl-p-v phenylenediamine, N,N'-di-3-octyl-p-phenylene diamine,

N,N-di-4-octyl-p-phenylene diamine, N,N-di-2-nonyl-p-'phenylene'diarnine, N,N-di-3-nonyl-p-phenylene diamine,N,N'-di-4-nonyl-p-phenylene diamine, N,N-di-2-decyl-pphenylene diamine,N,N'-di-3-decyl-p-phenylene diamine, N,N'-di-4-decyl-p-phenylenediamine, N,N-di-5-decyl-pphenylene diamine,N,N'-di-2-undecyl-p-phenylene diamine, N,N'-di-3-undecyl-p-phenylenediamine, N,N'-di- 4-undecyl-p-phenylene diamine,N,N-di-5-undecyl-pphenylene diamine, N,N-di-2-dodecyl-p-phenylenediamine, N,N-di-3-dodecyl-p-phenylene diamine, N,N-di-4-dodecyl-p-phenylene diamine, N,N-di-5-dodecyl-pphenylene diamine, etc.Other preferred inhibitors include N,N'-di-2-(5-methylheptyl)-p-phenylene diamine,N,N-di-2(6-methyloctyl)-p-phenylene diamine, N,N-di-2-(7-methylnonyl)-p-phenylene diamine, N,N'-di-2- (4- decyD-p-phenylehediamine, N,N-di-2-(4,8-dimethyldecyl)-p-phenylene diamine,N,N-di-2-(5,10-dimethylundecyl) -p-phenylene diamine,N,N-di-2-(4-methyldodecyl)-p-phenylene diamine,N,N-di-2-(4,9-dimethyldodecyl) -p-phenylene diamine,N,N-di-2-(4,7,l0-trimethyl-dodecyl) p phenylene diamine, N,N-di-3-(5-methyloctyl)-p-phenylene diamine,N,N'-di-3-(5,7-dimethyl-octyl)-p-phenylene diamine,N,N-di-3-(7-methylnonyl)-p-phenylene diamine,N,N'-di-3-(5,9-dimethyldecyl)-p-phenylene diamine,N,N-di-3-(6-ethyldecyl)-pphenylene diamine,N,N-di-3-(6,9-diethyl-undecyl)-pphenylene diamine,N,N-di-3-(G-methyldodecyl)-p-phenylene diamine,N,N'-di-3-(10-ethyl-dodecyl)-p-phenylene diamine,N,N-di-3-(5-ethyl-11-methyl-dodecyl)-p-phenylene diamine, etc.

In some cases, the inhibitor may contain two different alkyl groups,each containing at least 8 carbon atoms. Compounds in this class maycomprise, for example, N- octyl-N-nonyl-p-phenylene diamine,N-octyl-N'-decyl-pphenylene diamine, N-octyl-N'-undecyl-p-phenylenediamine, N-octyl-N'-dodecyl-p-phenylene diamine, etc., N-,nonyl-N'-decyl-p-phenylene diamine, N-nonyl-Nf-undecylp-phenylenediamine, N-nonylN'-dodecyl-p-phenylene diamine,N-nonyl-N'-tridecyl-p--phenylene diamine,. N-nonyl-N-pentadecyl-p-phenylene diamine, etc., N-decyl-N-undecyl-p-phenylene diamine, N-decyl-N'-dodecyl-pphenylene diamine,N-decyl-N-tridecyl-p-phenylene diamine,N-decyl-N'-pentadecyl-p-pl1enylene diamine, etc.

It will be noted that a large number of additive compounds may beprepared and used within the broad scope of the present invention.However, all of these compounds are not necessarily equivalent in theiractivity.

The additive compounds of the present invention may be prepared in anysuitable manner. 7 A particularly preferred method for preparing thesecompounds is by the reductive alkylation of p-nitroaniline orp-phenylene diamine with an aldehyde and preferably a ketone. Apreferred catalyst for effecting this reaction comprises a mixture ofthe oxides of chromium, copper and barium, although other suitablecatalysts may be employed. Other catalysts include those containingcobalt, nickel, platinum, palladium, molybdenum, etc. In general, thereaction is effected at an elevated temperature of from about 100 toabout 250 C. and a hydrogen pressure of from about 3 to about 200atmospheres.

The inhibitor of the present invention will be used in edible fats andoils and other food products in an amount sufiicient to obtain thedesired stabilization. In general, the concentration will be within therange of from about 0.000l% to about 1% by weight and more particularlywithin the range of from about 0.001% to about 0.5% by weight. It isunderstood that the inhibitor may be used in conjunction with synergistssuch as citric acid, phosphoric acid, ascorbic acid, etc., and/or withother approved oxidation inhibitors, such as 2-tert-butyl-4-niethoxyphenol, 2,6-di-tert-butyl-4-methylphenol, NDGA, propyl gallate,etc. The use of the inhibitor of the present invention along with otherinhibitors offers advantages in reducing the total amount of additiverequired, increasing solubility of the other inhibitors in the ediblefats and oils, etc. When desired, the inhibitor of the presentinvention, alone or in combination with the other additives, may beprepared as a solution in edible oil or other suitable non-toxicsolvents. V

The inhibitor may be incorporated in the edible fats and oils in anysuitable manner. When added to an edible oil or other food product inliquid state, the inhibitor is added thereto, preferably followed bysuitable mixing. When the food product is a solid, the inhibitor may beinjected therein, sprayed on, etc., or the food product may be soaked,dipped, immersed or suspended in the inhibitor or a solution or emulsionthereof.

The following examples are introduced to illustrate further the noveltyand utility of the present invention but not with the intention ofunduly limiting the same.

EXAMPLE I The inhibitor used in this example is N,N'-di-3-(5-methylheptyl)-p-phenylene diamine and was prepared by the reductivealkylation of p-nitroaniline with ethyl amyl ketone. The lard used inthis example had a normal stability period of two hours as determined bythe Swift test. This test is described in detail in the article appearedin Oil and Soap, pages 105-109, June 1933, and modified as described inthe article by R. W. Reimenby A. E. King, H. L. Roschen and W. H. Irwin,which 4 schneider, J. Turer and R. M. Spec, which, appeared in Oil andSoap, pages 169-171, September 1943. In general, this test comprisesbubbling air through a sample of the lard and determining rancidityorganoleptically and by peroxide values.

Different concentrations of the inhibitor were added to diiferentsamples of the lard, and the stability periods determined. These arereported in the following table:

Table I Additive: Stability period, hours None 2 0.01% by weight ofN,N'-di-3-(5-methylheptyl)-p-phenylene diamine 78.5 0.015% by weight ofabove inhibitor 116 0.02% by Weight of above inhibitor It will be notedthat the inhibitor of the present invention was very effective inincreasing the stability period of the lard.

EXAMPLE II EXAMPLE III A slab of bacon may be stabilized againstrancidity by soaking the same in a 20% solution ofN,N-di-2-tridecylp-phenylene diamine in lard oil for a time sufficientto incorporate a stabilizing amount of the inhibitor in the bacon.

EXAMPLE IV Egg plantmay be stabilized against oxidative deterioration byspraying the same with a 30% solution of N,N- di-3-(5-methyl-heptyl)-p-phenylene diamine in cotton seed oil. i

I claim as my invention:

1. A method of stabilizing a food product of animal origin againstrancidity which comprises incorporating therein a stabilizing amount ofN,N-di-alkyl-p-phenylene diamine inhibitor in which each alkyl groupcontains at least 8 carbon atoms.

2. A method of stabilizing a food product of animal origin againstrancidity whichcomprises incorporating therein a stabilizing amounts ofN,N-di alkyl-p-phenylene diamine inhibitor in which each alkyl groupcontains from about 8 to about 20 carbon atoms. l

3. A method of stabilizing a fatty material of animal origin againstrancidity which comprises incorporating therein a stabilizing amount ofN,N'-di-alkyl-p-phenylene diamine inhibitor in which each alkyl group,contains from about 8 to about 20 carbon atoms.

4. A method of stabilizing lard against rancidity which comprisesincorporating therein a stabilizing amount ofN,-N'-di-3-(5-methylheptyl)-p-phenylene diamine.

5. A method of stabilizing lard against [rancidity which comprisesincorporating therein a stabilizing amount ofN,N'-di-4-(2,6-dimethyl-heptyl)-p-phenylenea diamine.

6. A method of stabilizing lard against rancidity which comprisesincorporating therein a stabilizing amount ofN,N-d.i-2-decyl-p-phenylene diamine.

7. A method of stabilizing lard against rancidity which comprisesincorporating therein a stabilizing amount ofN,N'-di-2-tridecyl-p-phenylene diamine.

8. A method of stabilizing lard against rancidity which comprisesincorporating therein a stabilizing amount of anN,N-di-alkyl-p-phenylene diamine inhibitor having at least 8 carbonatoms in each of its alkyl groups.

9. Food product of animal origin stabilized against rancidity containinga stabilizing amount of an N,N'-digroup contains at least 8 carbonatoms.

10. Food product of animal origin stabilized against ranciditycontaining a stabilizing amount of an N,N'- di-alkyl-p-phenylene diamineinhibitor in which each alkyl group contains from about 8 to about 20carbon atoms.

11. Fatty material of animal origin stabilized against ranciditycontaining a stabilizing amount of N,Ndialkyl-p-phenylene diamineinhibitor in which each alkyl group contains from about 8 to about 20carbon atoms.

12. Fatty material stabilized against rancidity containing a stabilizingamounts of N,N'-di-3 (5-methylheptyl)-p-phenylene diamine.

13. Fatty material stabilized against rancidity containing a stabilizingamount of N,N'-di-4-(2,6-dimethy1- heptyl) -p-phenylene diamine.

14. Fatty material stabilized against rancidity containing a stabilizingamount of N,N'-di-2-decyl-p-phenylene diamine.

15. Fatty material stabilized against rancidity con- References Cited inthe file of this patent UNITED STATES PATENTS 2,498,630 Thompson Feb.28, 1950 2,513,002 Chenicek June 27, 1950 2,686,719 Ohenicek Aug. 17,1954

1. A METHOD OF STABLIZING A FOOD PRODUCT OF ANIMAL ORIGIN AGAINSTRANCIDITY WHICH COMPRISES INCORPORATING THEREIN A STABILIZING AMOUNT OFN,N''-DI-ALKYL-P-PHENYLENE DIAMINE INHIBITOR IN WHICH EACH ALKYL GROUPCONTAINS AT LEAST 8 CARBON ATOMS.